水体及土壤污染源氮硫磷及重金属汞砷铅镉综合检测仪的构建

The construction of simultaneous detector of nitrogen, sulfur, phosphorus ions and heavy metals mercury, arsenic, lead and cadmium in contaminated water and soil

构建了一台集取样、转化、分析的同步在线综合检测仪器,仪器构架原理基于紫外-可见光吸收检测污染源的氮硫磷水平(氨氮,PO_(4)^(3-),SO_(4)^(2-))、基于原子荧光检测Hg,As,Pb,Cd等4种有害重金属。对于水体污染源可以自动采集污水样品后直接检测;于土壤污染水平评价设计了土柱实验单元转移土壤污染物至液相,土柱实验还可协同完成土壤理化物性参数测定(如渗漏系数及吸附解离系数等)。实验结果表明,所关注各种污染物的检测标准曲线线性度良好,R^(2)均大于0.99,氮硫磷离子检测精度达到1μg/mL,重金属检测精度达到0.1~0.01 ng/mL;土柱实验正确地显示渗流液中选取的重金属As和Cd浓度随时间下降、最后平缓的总体趋势,在试验条件下,As和Cd的质量浓度平衡值分别为1.75 ng/mL和0.013 ng/mL。开放的仪器构架可以扩展检测更多污染物,如全氮污染物(总氮、硝酸盐及亚硝酸盐)和亚硫酸盐、Cr等,模块化设计可实现基于量子点荧光原理的重要矿产元素如稀土元素分析。

This study demonstrated a synchronous comprehensive detection instrument integrating with sampling, speciation and detection sub-system, which was based on automation design, the ultraviolet-visible spectrophotometry and atomic fluorescence spectrophotometry.The detection of common and representative pollutants in water and soil include ammonia nitrogen, phosphate, sulfate, and heavy metals such as mercury, arsenic, lead and cadmium. Among of them, the water detection unit is core sector, and a soil column test unit fulfills the interaction between contaminated soil and contacting water, which was consequently analyzed using the water detection unit. By this means, the pollution level of soil was given by the transformation of pollutants in the soil to the contacting water. Meanwhile, physical parameters such as adsorption and desorption coefficients and permeability coefficient can be obtained.The test results showed well linearity of the standard curve of each pollutant, with R^(2)above 0.99. This automation of instrument greatly reduces the cumbersome manual operation and thus improves the analysis efficiency. In a perspective view, the construction of this instrumental device could be further extended to involve more analysis units.